Discharge head utilizing a pressure-responsive detent mechanism

ABSTRACT

A pressure responsive discharge head wherein the expellable plug is disposed in the outlet of a body member having an inlet adapted for connection to a source of fluid under pressure, with the plug being connected relative to the body member by means of a detent mechanism. Upon a predetermined temperature being attained in the vicinity of the head, as well as a predetermined pressure existing in the body member, the connection provided by the detent mechanism is broken and the plug is released from the outlet to permit the fluid to be discharged from the nozzle.

United States Patent Zenker [451 Dec. 12,1972

[54] DISCHARGE HEAD UTILIZING A PRESSURE-RESPONSIVE DETENT MECHANISM[72] lnventor: Karol R. Zenker, Needham,Mass.

[73] Assignee: Factory Mutual Research Corporation, Norwood, Mass.

22 Filed: Sept. 8, 1971 21] Appl.No.:178,734

[52] US. Cl. ..239/452, 137/70, 169/37 [51] .Int. Cl. ..B05b 1/32 [58]Field of Search ..239/452, 456, 534; 169/37,

[56] References Cited UNITED STATES PATENTS 2,414,127 1/1947 Shaw..l69/38 3,288,224 11/1966 Trudeau ..l69/42X 3,289,686 12/1966 Tyer,Jr...169/42X 3,655,136 4/1972 Livington ..l69/37X Primary Examiner-M.Henson Wood, Jr. Assistant Examiner-Michael Y. Mar Attorney-Joseph M.Lane et a1.

[5 7] ABSTRACT A pressure responsive discharge head wherein theexpellable plug is disposed in the outlet of a body member having aninlet adapted for connection to a source of fluid under pressure, withthe plug being connected relative to the body member by means of adetent mechanism. Upon a predetermined temperature being attained in thevicinity of the head, as well as a predetermined pressure existing inthe body member, the connection provided by the detent mechanism isbroken and the plug is released from the outlet to permit the fluid tobe discharged from the nozzle.

14 Claims, 2 Drawing Figures PAIENTEDuEm m2 3.705.691

FIG].

INVENTOR KAROL R. ZENKER WM @W A ORNEYS 1 DISCHARGE HEAD UTILIZING APRESSURE- RESPONSIVE DETENT MECHANISM BACKGROUND OF THE INVENTION Thefire fighting capability of typical prior art fire protection systemsemploying a number of sprinkler heads mounted in an elevated position inthe enclosure to be protected is often curtailed when the system is in--stalled in relatively large storage facilities, such as warehouses, etc.One of the reasons for this is due to the fact that these large storageenclosures often contain very high stacks of combustible materials whichfrequently are highly inflammable. As a result, upon the development offire in the enclosure, fire plumes or columns of feet'and higher mayflare out beneath the ceiling of the enclosure and actuate numeroussprinkler heads located at such a distance from the fire that they areineffective to deliver water or other extinguishant to the surfaces ofthe combustible materials. This contributes not only to redundant andflooding use of the water, but, more significantly, robs water from theheads over the fire where it is needed to extinguish the fire.

In. US. Pat. application Ser. No. 72,333, filed on Sept. 15, 1970, nowPat. No. 3,653,444 by the same inventor and assigned to the sameassignee as the present application, a fixed fire extinguishing systemis disclosed which is designed to limit the number of sprinkler headswhich will be activated by a fire. The heads are spaced apart greaterdistances and have large outlet orifices to enable greater quantities ofwater or other extinguishant to be delivered from each head at lowerflow rates. Preferably, the heads are in the form of wide angle spraynozzles which develop a downwardly directed spray having large sizedroplets as compared to the droplets produced by the conventionalsprinkler heads.

With this arrangement, the first nozzle actuated by the fire has a muchbetter possibility of extinguishing the fire, because of the ability toretain a predetermined discharge density and the increased ability ofthe larger droplets to penetrate the fire plume of a high challengefire. If the heat of the fire spreads, additional nozzles are actuatedto help the first nozzle fight the fire and to wet down areassurrounding the fire to provide exposure protection to inhibit thespread of the tire. However, the additional nozzles which are allowed tobe actuated are limited to a small predetermined number to avoid theprior art problems created by two many heads being actuated; namely,interfering with the fire fighting capabilities of those nozzlespositioned immediately above the fire and over the area immediatelysurrounding the fire by reducing the discharge density, and causingunnecessary water damage by allowing an excessive number of nozzles tobe actuated at points remote from the fire. In accordance with apreferred embodiment of the abovementioned application, the above isachieved by establishing a pressure floor so that a minimum pressuremust exist at each nozzle before it will open. The system is designed sothat this minimum pressure will not be reached until a predeterminednumber of nozzles have been opened.

Although this embodiment results in several advantages includingincreased fire fighting capability and significant cost savings inseveral respects, it suffers from one disadvantage. Specifically, inestablishing the above-mentioned pressure floor, an expellable plugnormally blocks the outlet of the nozzle and is adapted to be expelledfrom the nozzle to permit extinguishant flow therethrough upon thefusing of a conventional temperature responsive device and the presenceof a fluid pressure in the nozzles of a magnitude exceeding apredetermined value. In establishing the latter value, a helicalcompression spring is utilized to latch the expellable plug in a closedposition. The design is such that the extinguishant pressure in thenozzle acts upon the helical spring and must be of a value to overcomethe force of the spring before the expellable plug can be released.However, it has been discovered that the use of the above-mentionedspring makes it extremely difficult to ascertain the precise pressurerequired to overcome the force of the spring. This is largely due to thefact that it is extremely difficult to obtain a compression spring thatwill achieve a predictable result at a cost compatible with this typesystem. It can be appreciated that this renders the overall design andoperation of the system extremely unpredictable.

SUMMARY OF THE INVENTION It is therefore an object of the invention toprovide a pressure floor system of the above type which eliminates theuse of a compression spring, and which enables the plug from the nozzleto be expelled in response to a precise predetermined finite fluidpressure occurring in the nozzle.

Towards the fulfillment of this object, the nozzle of the presentinvention comprises a body member having an inlet for a source of fluidunder pressure, an outlet for discharging said fluid, plug meansdisposed in said outlet, and detent means for locking said plug meansrelative to said body member and responsive to a predetermined fluidpressure in said body member for releasing the plug means from the bodymember to permit expulsion of the plug means from the outlet.

BRIEF DESCRIPTION OF THE DRAWINGS Reference is now made to theaccompanying drawings for a better understanding of the nature andobjects of the present invention.'The drawings illustrate the best modepresently contemplated for carrying out the objects of the invention andare not to be construed as restrictions or limitations on its scope. Inthe drawings:

FIG. 1 is a vertical crosssectional view of the nozzle of the presentinvention; and

FIG. 2 is an enlarged partial view similar to FIG. 1 and showing adetail of the nozzle of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The nozzle of the presentinvention will be described by way of example in connection with a fixedfire extinguishing system, wherein the nozzle is adapted for receivingand discharging a tire extinguishant in response to information receivedfrom a fire occurring in a particular structure in which the nozzle ismounted. Referring to FIGS. 1 and 2, the nozzle is shown in general bythe reference numeral 10 and comprises a cylindrical body 12 having anupper end portion which is internally threaded as shown at 14 forconnection to a source of extinguishant, such as water, and a lower endportion which defines an outlet orifice 16 of 'a reduced crosssection. Apair of spiral vanes 18a and 18b are fixed within the body 12 forimparting a swirling motion to the water flowing downwardly therethroughin a conventional manner. The vanes 18a and 18b support a hollow centralhub 20 which, in turn, slidably supports a rod 22 having a plug member24 fixed on its lower end and extending in the outlet orifice 16. Asealing ring 26 is positioned about the periphery of the plug member 24and sealingly engages the inner wall of the body 12 near the outletorifice 16.

The rod 22 is latched in the position shown in FIG. 1 by a rod 32 whichextends slidably through an externally threaded boss .34 projecting fromthe side of the body 12. One end of the rod 32 extends through the vanc18b and the wall of the central hub 20 into a tapered hole 36 in the rod22 to latch it in the position shown.

A sleeve 38 is threaded on the end of the boss 34. The outer end of thesleeve is closed off by an externally threaded stub shaft 40 having aring or yoke 42 thereon. The rod 32 slidably extends through the stubshaft 40, and the other end of the rod engages a conventional fusiblelink assembly 44 positioned within the ring 42. The assembly 44 preventsmovement of the rod 32 to the'right as viewed in FIG. 1, until the headof a fire fuses a portion of the assembly and causes it to collapse.Since the assembly 44 is the standard type commonly used in conventionalsprinkler heads now on the market, it will not be described in greaterdetail.

The rod 32 has a piston head 46 mounted thereon which slidably engagesthe internal wall of the sleeve 38. A spring 48 is positioned betweenthe boss 34 and the piston head 46 to bias the piston head and the rod32 to the right with a predetermined biasing force.

With this arrangement, the piston head 46 and the rod 32 will be drivento the right under the action of the spring 48, upon the link assembly44 collapsing in response to the heat of the fire and thus unlatch therod 22.

A detent mechanism is provided for locking the rod 22, and therefore theplug member 24, in the position of FIG. 1. This detent mechanism isbetter depicted in FIG. '2, and comprises a sleeve 56 disposed on theupper portions of the vanes 18a and 18b, and having a reduced portion56a which extends into a counterbore formed in the upper end portion ofthe hub 20. A set screw 58 extends through the latter upper end portionand engages in a channel formed in the reduced portion 56a of the sleeve56 to secure the latter in a concentric position within the hub 20. Thehollow portion of the sleeve 56 receives the upper end portion of therod 22 with a slight clearance being provided to permit movement of therod relative to the sleeve.

A plurality of spring-loaded balls 60 are supported by the sleeve 56 andengage the rod 22. A preferred embodiment would utilize four such ballsspaced at 90 intervals, and since the balls and their supportingstructure are identical, only two are shown and one described in detail,for the convenience of preparation.

In particular, the ball 60 is supported in one end of a radial bore 62formed through the sleeve 56, and a high-compression spring 64 isdisposed in the bore 62 and urges the ball outwardly from the end of thebore, with a tapered shoulder 62a being formed at the end of the bore toprevent complete discharge of the ball from the bore. A ball 66 issupported in the outer end of the bore 62 and slidably engages the wallsthereof so .that its position in the bore can be adjusted in order tovary the compressive load on the spring. One portion of the ball 66projects from the end of the bore 62, and another diammetricallyopposite portion is engaged by an appropriately formed end of the spring64 to center the latter in the bore 62.

A continuous groove 69 is formed around the cir-.

cumference of the rod 22 near the upper end thereof in alignment withthe ball 60. In this manner, the spring 64 urges a portion of the ball60 into the groove 69 to lock the rod 22 relative to the body member 12,with the magnitude of the locking force being determined on all positionof the ball 66 in the bore 62 and the resultant compression of thespring 64.

A cap 70 extends over the sleeve 56 and has an externally threaded plugportion 72 which engages corresponding threads formed in the upperportion of the bore in the sleeve 56. The internal wall of the cap 70has a tapered inner surface 74 which engages the ball 66. As a result,rotation of the cap 70 will cause it to move axially relative to thesleeve 56 and cause a corresponding variation in the amount of cammingforce applied to the ball 66 by the tapered inner surface 74. This, inturn, regulates the load on the spring 64 and the locking force appliedto the rod 22 by the ball 60.

Since the sleeve 56 and the cap 70 are both concentrically alignedrelative to the rod 22, the load on each ball 60 can be regulated to anexact degree in order to precisely adjust the amount of force requiredto release the rod 22 and therefore the plug member 24 from the detentmechanism.

In operation, the nozzles 10 of the entire fire protection system areinstalled at an elevated position in the structure to'be protected inthe condition shown in FIGS. 1 and 2, i.e., with each nozzle having itsrod 32 extending in the tapered hole 36 of the rod 22, with the balls 60extending in the groove 69 formed in the rod 22, and with the cap 70adjusted to a predetermined position relative to the sleeve 56 tocontrol the compression of the spring 64 and therefore the load on theballs 60.

If the fusible link assembly 44 is thermally actuated in response to anelevated temperature in its vicinity, the tension of the spring 48causes the rod 32 to release the rod 22. The extinguishant pressure inthe body member 12 acting on the inner end face of the plug member 24forces it downwardly as viewed in HO. 1, in direct proportion to theamount of pressure. If the force acting on the plug member 24 as aresult of this pressure exceeds the locking force applied to the rod 22by the spring-loaded balls 60, the rod 22 will be released, and it,along with the plug member 24, will discharge outwardly from the bodymember 12 under the force of the extinguishant Pressure. Of course, ifthe extinguishant pressure is not sufficient to overcome the lockingforce provided by the spring-loaded balls 60, the plug member 24 willnot be expelled from the body portion 12 despite the collapse of thefusible link assembly 44.

ln this manner, the number of nozzles that are actuated will be limitedby the extinguishant pressure available, and the fire fightingcapability of those nozzles positioned immediately above the fire andover the area immediately surrounding the fire will not be curtailed.Also, the unnecessary water damage resulting from an excessive number ofnozzles being actuated at points remote from the fire will beeliminated, as discussed above.

It can be appreciated that several variations may be made in theforegoing with departing from the scope of the invention. For example,the number of springloaded balls 60, and corresponding structure, can bevaried in accordance with particular design requirements. Of course,still other variations of the specific construction and arrangement ofthe nozzle disclosed above can be made by those skilled in the artwithout departing from the invention as defined in the appended claims.

lclaim:

l. A discharge head comprising a body member having an inlet for asource of fluid under pressure, an outlet for discharging said fluid,plug means disposed .in said body member for preventing the discharge offluid from said outlet, and detent means for locking said plug meansrelative to said body member, said detent means being adapted to releasesaid plug means from said body member in response to a predeterminedfluid pressure in said body member to permit the discharge of fluid fromsaid outlet.

2. The head of claim 1 wherein said detent means is in the form of atleast one spring-loaded locking element supported by one of said membersand engaging the other of said members.

' 3. The head of claim 2 further comprising adjusting means foradjusting the load on said locking element to vary said predeterminedfluid pressure.

4. The head of claim 3 wherein said plug means comprises a rod portionand a head portion, said locking element being in the form of a ballhaving a portion extending in a groove formed in said rod portion.

5. The head of claim 4 wherein said adjusting means comprises a sleevemounted in said body member in a concentric relationship with said rodportion and adapted to receive an end portion of said rod portion, saidsleeve having a bore formed in the wall thereof for receiving said balland the spring for said ball, said bore being aligned with said groovein the locking position of said detent means.

6. The head of claim 5 wherein said adjusting means further comprises acam follower slidably supported in said bore and engaging said spring,and camming means engaging said cam follower and adapted to vary theposition of said cam follower in said bore to vary the resultingcompression of said spring and the resulting load on said ball.

7. The head of claim 6 wherein said adjusting means further comprises acap concentrically disposed relative to said sleeve and in threadedengagement therewith, an inner wall of said cap having a tapered surfacewhich engages said cam follower and forms said camming means, wherebyrotation of said cap varies the position of the cam follower in saidbore.

8. The head of claim 7 wherein a plurality of said balls are supportedby said body member and engage said plug means, whereby rotation of saidcap effects a uniform variation in the load on said balls.

9. The head of claim 1 further comprising latching means for retainingsaid plug means in said body member and means responsive to apredetermined temperature in the vicinity of said head for releasingsaid latching means.

10. The head of claim 1 wherein said detent means comprises lockingmeans mounted relative to said body member and engaging said plug means,and camming means engaging. said locking means for applying a force tosaid plug means to lock said plug means relative to said body member.

11. The head of claim 10 wherein. said camming means comprises a cap inthreaded engagement with saidbody member, said cap having a taperedsurface for engaging said locking means, whereby rotation of said capvaries the relative position between said tapered surface and saidlocking means to adjust said force and vary said predetermined pressure.

12. The head of claim 11 wherein said locking means comprises aplurality of locking members spaced around said plug means and inengagement therewith, and a spring extending between each locking memberand said tapered surface, wherein said rotation of said cap uniformlyvaries the force applied to said plug means by each locking member.

13. A discharge head comprising a body member having an inlet for asource of fluid under pressure, an outlet for discharging said fluid,plug means disposed in said body member for preventing the discharge offluid from said outlet, at least one locking member supported by saidbody member and engaging said plug means, a camming member threadablyengaging said body member and defining a camming surface, and a camfollower engaging said camming surface and said locking member forurging said locking member into engagement with said plug means to applya predetermined force to said locking member and lock said plug meansrelative to said body member in the absence of a fluid pressure in saidbody member of a value that overcomes said force, whereby rotation ofsaid camming member varies the force applied to said plug means by saidlocking member.

14. The head of claim 13 wherein there are a plurality of lockingmembers spaced around said plug means in engagement therewith, saidrotation of said camming member uniformly varying the force applied tosaid plug means by said locking members.

1. A discharge head comprising a body member having an inlet for asource of fluid under pressure, an outlet for discharging said fluid,plug means disposed in said body member for preventing the discharge offluid from said outlet, and detent means for locking said plug meansrelative to said body member, said detent means being adapted to releasesaid plug means from said body member in response to a predeterminedfluid pressure in said body member to permit the discharge of fluid fromsaid outlet.
 2. The head of claim 1 wherein said detent means is in theform of at least one spring-loaded locking element supported by one ofsaid members and engaging the other of said members.
 3. The head ofclaim 2 further comPrising adjusting means for adjusting the load onsaid locking element to vary said predetermined fluid pressure.
 4. Thehead of claim 3 wherein said plug means comprises a rod portion and ahead portion, said locking element being in the form of a ball having aportion extending in a groove formed in said rod portion.
 5. The head ofclaim 4 wherein said adjusting means comprises a sleeve mounted in saidbody member in a concentric relationship with said rod portion andadapted to receive an end portion of said rod portion, said sleevehaving a bore formed in the wall thereof for receiving said ball and thespring for said ball, said bore being aligned with said groove in thelocking position of said detent means.
 6. The head of claim 5 whereinsaid adjusting means further comprises a cam follower slidably supportedin said bore and engaging said spring, and camming means engaging saidcam follower and adapted to vary the position of said cam follower insaid bore to vary the resulting compression of said spring and theresulting load on said ball.
 7. The head of claim 6 wherein saidadjusting means further comprises a cap concentrically disposed relativeto said sleeve and in threaded engagement therewith, an inner wall ofsaid cap having a tapered surface which engages said cam follower andforms said camming means, whereby rotation of said cap varies theposition of the cam follower in said bore.
 8. The head of claim 7wherein a plurality of said balls are supported by said body member andengage said plug means, whereby rotation of said cap effects a uniformvariation in the load on said balls.
 9. The head of claim 1 furthercomprising latching means for retaining said plug means in said bodymember and means responsive to a predetermined temperature in thevicinity of said head for releasing said latching means.
 10. The head ofclaim 1 wherein said detent means comprises locking means mountedrelative to said body member and engaging said plug means, and cammingmeans engaging said locking means for applying a force to said plugmeans to lock said plug means relative to said body member.
 11. The headof claim 10 wherein said camming means comprises a cap in threadedengagement with said body member, said cap having a tapered surface forengaging said locking means, whereby rotation of said cap varies therelative position between said tapered surface and said locking means toadjust said force and vary said predetermined pressure.
 12. The head ofclaim 11 wherein said locking means comprises a plurality of lockingmembers spaced around said plug means and in engagement therewith, and aspring extending between each locking member and said tapered surface,wherein said rotation of said cap uniformly varies the force applied tosaid plug means by each locking member.
 13. A discharge head comprisinga body member having an inlet for a source of fluid under pressure, anoutlet for discharging said fluid, plug means disposed in said bodymember for preventing the discharge of fluid from said outlet, at leastone locking member supported by said body member and engaging said plugmeans, a camming member threadably engaging said body member anddefining a camming surface, and a cam follower engaging said cammingsurface and said locking member for urging said locking member intoengagement with said plug means to apply a predetermined force to saidlocking member and lock said plug means relative to said body member inthe absence of a fluid pressure in said body member of a value thatovercomes said force, whereby rotation of said camming member varies theforce applied to said plug means by said locking member.
 14. The head ofclaim 13 wherein there are a plurality of locking members spaced aroundsaid plug means in engagement therewith, said rotation of said cammingmember uniformly varying the force applied to said plug means by saidlocking members.